Hydrochloric Acid → tert-butyl N-(6-chloro-3-formylpyridin-2-yl)carbamate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

The reaction apparatus was dried by heating, and the reaction was carried out under argon with stirring. 15 g (65.6 mmol) of tert-butyl (6-chloropyridin-2-yl)carbamate (Example 24A) and 19 g (164 mmol) of 1,2-bis(dimethylamino)ethane were initially charged in 270 ml of THF and cooled to −78° C. 102.5 ml (164 mmol) of butyllithium (1.6N) were added dropwise. After the dropwise addition had ended, the reaction was slowly warmed to −10° C. and kept at −10° C. for 2 h. The mixture was then once more cooled to −78° C., and 10 ml (131 mmol) of DMF were added. The reaction was slowly warmed to RT, the reaction mixture was added to 1 l of ethyl acetate and 350 ml of 1N hydrochloric acid and stirred for 15 min and the organic phase was separated off. The organic phase was washed with water and saturated sodium bicarbonate solution, dried over magnesium sulfate and concentrated on a rotary evaporator. Diethyl ether was added to the residue, and the solid was filtered off with suction and dried. This gave 12.3 g (73% of theory) of the product as a solid.

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